A surveyor can split acreage on paper in an afternoon. Whether each piece can hold a house, two drainfields, and a well is a soil question, and it's much cheaper to answer before the lines are drawn.
It depends on lot size. If any new lot is under five acres and will use septic, TDEC must approve the septic plans before planners can approve the split. If every tract is five acres or larger, that state review doesn't apply. Either way, each future house still needs its own septic construction permit, so map the soil first.
Tennessee's septic rule defines a subdivision as land divided into two or more lots for building where septic will be used. The same definition leaves out any division where every resulting tract is five acres or larger. So a split into all 5-plus-acre tracts skips the state's subdivision-level septic review.
That's all it skips. Nobody has checked the soil, reserved a drainfield, or approved a house. When you or a buyer goes to build, TDEC still has to issue a construction permit for that lot, and five acres of shallow rock, sinkholes, or steep slope can still fail. County planning and zoning rules also still apply.
| How the land is split | State septic subdivision review? | What still has to happen |
|---|---|---|
| Any lot under 5 acres, on septic | Yes. Rule 0400-48-01-.03 bars planning approval until TDEC approves the septic plans | County or city plat approval, then a construction permit for each house |
| Every tract 5 acres or larger | No, under the SSDS definition | County or city rules, then a construction permit for each house |
| Lots on public sewer | Not a septic question | Utility capacity and connection approval |
From the definition of "subdivision" in Tennessee Rule 0400-48-01-.02. Ask TDEC's Columbia Environmental Field Office how it applies to your exact division.
Mark the lots you want, road frontage or access, any existing house and septic, wells, and drainage.
Find out whether county or city planning controls the land and whether public sewer is available.
Get deeds, old surveys and plats, TDEC septic records for any existing home, and flood or sinkhole information.
Hire a TDEC-approved soil consultant to map the tract. Leave the lines flexible so each lot can wrap around its primary and duplicate field areas.
Let the soil map, slopes, well spots, setbacks, and driveways shape the boundaries. Fix weak lots now.
Send TDEC and the planning office what each requires. They review separately.
Carry forward any approved bedroom limits, septic areas, easements, and the required septic notations.
Before building, get the lot-specific TDEC construction permit for the actual house and bedroom count.
Good soil rarely lines up with the rectangles a landowner first sketches. In Maury County, one ridge may have plenty of depth while the slope next to it hits limestone in a couple of feet. A drainageway, sinkhole, or road cut can sit right between the usable soil and the best house site.
Equal-acre lots drawn first can leave one lot with all the road frontage and the next one with all the good soil. A soil-first plan lets the surveyor bend the lines so every lot gets a house site, both fields, and a well spot that keeps its 50 feet.
The soil consultant documents conditions. TDEC and the planning office make the approvals.
| What you gather | Question it answers | Mistake it prevents |
|---|---|---|
| Boundary and topographic survey | Where are the lines, grades, roads, and easements? | A legal lot that can't physically hold the layout |
| TDEC records | Where are existing tanks, fields, and duplicate areas? | Cutting through the existing home's septic |
| High-intensity soil map | Where is suitable soil, and how deep? | Assuming every lot has a conventional field |
| Concept septic layouts | Does each lot fit a primary and duplicate field with setbacks? | Treating a soil polygon as a buildable lot |
| Well plan | Can each well keep 50 feet from every tank and field, including the neighbor's? | A well conflict found after the lines are fixed |
| Road and drainage plan | Will cuts, culverts, and ditches miss the field areas? | Grading away the approved soil |
Tennessee's subdivision rule (0400-48-01-.03) sets the real test: every lot has to be big enough for the original septic system and a full duplicate, sized for a conventional system with 36-inch trenches unless an alternative system is used. Where subdivision lots are approved on perc tests rather than a soil map, the rule adds a floor of 20,000 square feet with public water or 25,000 square feet with a private well.
In unincorporated Maury County, lots without sewer must meet the zoning district's minimum or TDEC's requirement, whichever is larger. In practice, the real minimum is whatever it takes to fit the house, a primary field, a full duplicate field, and the setbacks.
The county zoning ordinance that took effect January 1, 2026 lets owners in the AP (agricultural) district create lots for immediate family under a separate set of standards.
| Family subdivision rule | Standard |
|---|---|
| Parent tract | Must stay at least 15 acres |
| Lots allowed | 4 extra lots from 15 to under 25 acres, 5 from 25 to under 50, 6 at 50 acres or more |
| Minimum lot | Half an acre, 130 feet wide |
| Setbacks | 30 feet front, 10 feet side, 30 feet rear |
| Access | A public road or an easement at least 50 feet wide serving no more than five lots |
| Transfer limit | A covenant bars sale outside the immediate family for 15 years, with exceptions such as foreclosure or death |
From Maury County Zoning Ordinance Section 4.2.4(A)(1). A half-acre family lot under five acres is still a subdivision for TDEC septic purposes, and it still needs room for both drainfields.
Start with the TDEC permit, then confirm it in the field. Older sketches can be rough, and repairs may have moved things. Locate the tank, the sewer line, the active field, the duplicate area, any pump, and the well before the surveyor draws anything.
Maury County's zoning ordinance says every septic system and field has to be on the same lot as the use it serves, not on another lot or in an easement. So the existing home's field can't end up on the child's lot or straddle a new line. Leave room for a pump truck and a future repair too.
| Scenario | Hidden septic risk | Better move |
|---|---|---|
| Giving a child a homesite | The chosen corner has access but no room for two fields | Map soil before promising the boundary |
| Keeping the house and selling the back acreage | The sale parcel takes the existing duplicate field | Locate the whole system and draw the retained lot around it |
| Splitting for an estate | Ownership changes before anyone checks buildability | Add soil and access review to the estate plan |
| Creating spec-home lots | The homes you want exceed what the approved areas support | Design homes to the approved lot capacity |
| Building an ADU now, splitting later | A shared system blocks separate ownership | Plan the ADU's septic on its future lot |
Plan for the survey, soil mapping, planning submissions, plat revisions, recording, roads, drainage, and legal work. Tough sites can add karst investigation or engineered septic concepts.
Don't price septic installation for every lot off the soil map alone. The house plan and the construction permit set the real scope, so carry a per-lot allowance until those exist.
About our sources. Maury Septic uses the sources listed below, including Tennessee's SSDS subdivision definition and five-acre exclusion, perc-test lot minimums, Maury County's 2026 family-subdivision and same-lot rules, soil-first layout, and protecting an existing system. Follow the links for the underlying rules, fees, and guidance.
Tennessee Department of Environment and Conservation
Conventional, repair, and alternative-system applications, plus soil-map requirements.
Tennessee Secretary of State
Official current chapter text governing Tennessee subsurface sewage disposal systems.
Tennessee Department of Environment and Conservation
What an approved consultant evaluates, current qualification rules, and the state consultant list.
Tennessee Department of Environment and Conservation
State mapping standards for soil depth, restrictive layers, drainage, absorption rates, slope, site features, and SSDS interpretations.
Tennessee Department of Environment and Conservation
Who needs a permit, application requirements, review timing, current state fees, and inspection duties.
Tennessee Department of Environment and Conservation
Official state viewer for locating septic-system permits, site sketches, and related records.
Maury County Government
Current county subdivision process, plat certificates, private sewage-disposal approval, and final-plat requirements for land under county planning jurisdiction.
Maury County Government
Current zoning rules for unincorporated Maury County, including lot standards and the requirement that septic systems and fields remain on the lot they serve.
Tennessee Geological Survey
State-published geologic, unstable-materials, flood-prone-area, mineral-resource, and sinkhole maps for Maury County.
Bring the surveyor in early for topography and existing features, but keep the lines flexible until the soil is mapped. Final boundaries should follow the soil so each lot fits a house, a primary field, a duplicate field, a well, and a driveway.
Tennessee commonly uses a soil map by an approved consultant rather than a simple pass-or-fail perc test. A covered subdivision is mapped and reviewed as a project, and each house still gets its own construction permit. Ask TDEC what mapping your division needs.
No. In unincorporated Maury County the system and field must stay on the same lot as the home they serve. The line also has to respect setbacks, the duplicate area, and access for repairs. Locate the system before the surveyor finalizes anything.
No. It only takes a split into all 5-plus-acre tracts out of TDEC's subdivision-level review. Anyone who builds a house on one of those tracts still needs a TDEC construction permit based on that lot's soil.
Talk to a Tennessee real estate attorney first. Be exact about what stage you're at: a soil map, a preliminary plan, a recorded plat, and a construction permit are four different things. Buyers should get soil, access, and permit contingencies in writing.
Share the recorded plat, soil information, TDEC construction permit, and house plan. If a licensed installer who works on new lots can take it, we'll pass it on. This form doesn't map soil, approve a subdivision, or issue permits.
Related: soil and site evaluation · setbacks and usable lot area · new construction sequence · find existing septic records · ADUs and future lot splits · well and septic distance
Keep your permit, system sketch, and service records together. They help the next professional understand your property.